Hi,

I have designed an amplifier for FM band (87.5-108 MHz) with a good IP3 (+64 dBm) but now my goal is to increase the IP3 to +70 dBm.

My amplifier use two transistor in push-pull, a MRF136Y and a D1008UK with a ferrite transformer before the MRF136Y, a coax transformer between both, and a coax transformer and a coax balun after the D1008UK. I have used coax transformer to get a good IP3 in all FM band and to potentialy use this amplifier in other band.

I'm looking for basic advice, about design of an amplifier with good IP3.
Joss

 

A schematic might help, but I would start by looking at this -> ferrite transformer

 

Do you have to stay with that circuit? I recommend the Tayloe detector/mixer.....or what ever you want to call it.

It's simple and low component count.....but needs a high frequency local oscillator.

The specs are impressive. Tayloe Mixer. But is really a simple switch.